I like .40, and yeah it's ridiculous to call it a flash in the pan, or even say it's dead now.
For over 20 years if a new handgun came out, it was in .40, with 9mm being the gimme.
It's not the hot thing, but give it a couple years and all the cheap police-trade ins, it will wind up like 10mm & 5.7, going through a resurgence as people get bored.